For most clinical diagnosis assay devices for detecting a small amount of sample, multiple sample preparation and automatic reagent addition devices have been developed and a device having a parallel or series structure can assay many test samples, in order to increase efficiency and economic efficiency. Usually, such automatic reagent preparation devices and automatic assay devices are integrated in a single thin film device. Such a thin film device for clinical trials is used to automatically or manually perform hundreds of assays by using a small amount of sample and reagent within one hour. Thin film devices for clinical trials necessarily include valves for automatically loading the sample and/or reagent, such as an enzyme or a buffer solution. However, designing valves are complex and thus forming thin-film devices including such valves is difficult. Accordingly, to overcome these problems, a simple valve that is appropriate for thin-films is needed to be developed.
A standard compact disc is formed by using a 12 cm-polycarbonate substrate, a reflective metal layer, and a protective lacquer coating method. The format of DVDs, CDs, and CD-ROMs is described in the ISO 9660 industrial standard. The polycarbonate substrate may be formed of transparent polycarbonate having an optical quality. A portion of the polycarbonate substrate constitutes a data layer of the DVD or CD and data is stored in the data layer in a series of pits formed by engraving with a stamper in an injection molding process. Generally, a stamping master is formed of glass. The polycarbonate substrate can be modified into a thin film assay device, such as a bio disk, for diagnosing and detecting a small amount of material in a fluid. In this case, in the injection molding process, on a surface of a disk, a channel through which a fluid flows and a chamber in which a buffer solution is to be contained are formed instead of pits. Accordingly, a thin film valve can be needed to smoothly control the flow and/or amount of a fluid flowing through the channel formed in the thin film assay device.
Hereinafter, a disk in which a bio chip, such as a lab-on-a-chip, a protein chip, or a DNA chip, for diagnosing and detecting a small amount of a bio material in a fluid, which is formed by modifying a conventional disk, such as CD-ROM or DVD, and a thin film valve are integrated together; or a disk for performing a bio and chemical process to diagnose and detect a small amount of a bio material in a fluid by integrating a thin film valve will be referred to as a “bio disk” or “thin film bio valve device”.
A device for assaying a fluid by using a centrifugal force of a specimen loaded through an inlet of a disk has been developed. In addition, a device for separating a specimen loaded through an inlet of a disk by moving the specimen to a channel and a chamber due to a centrifugal force has been developed. However, for these devices, it is difficult to manufacture valves having a thin film structure and thus, the amount of the fluid cannot be accurately controlled.
In general, known valves using an electromagnet open or close a channel by using a cylinder or plunger that moves due to a magnetic force. However, to obtain sufficient magnetic force to move the cylinder or plunger, a suitably sized ferrite core and many coils to be wound thereon are needed, and a large amount of electricity may also be needed when valves are on and off to move the cylinder and plunger. Thus, these valves using an electromagnet cannot be manufactured to have a thin film structure due to the size of the electromagnet. In addition, since heat is generated due to high power consumption, unique properties of a fluid may be changed, which is a problem for diagnosing and/or detecting a small amount of material in a fluid. These valves using an electromagnet are known. To overcome these problems, an embodiment of the inventive concept uses, instead of an electromagnet, a magnetic valve and a movable permanent magnet to open or close the channel hole. Thus, in this case, electricity for generating a magnetic force is not needed and heat is not generated, and thus unique properties of a fluid are not changed.
A thin film bio valve device according to an embodiment of the inventive concept enables formation of a super-thin-film valve and integration of many valves in a unit area. Accordingly, the thin film bio valve device according to an embodiment of the inventive concept may constitute a valve structure of a thin film device, such as a lap-on-a-chip or a DNA chip, for diagnosing and/or detecting a small amount of a material included in a fluid.
For example, the thin film bio valve device according to an embodiment of the inventive concept may constitute a micro valve apparatus for opening and closing a channel hole formed in a thin film body by modifying a conventional disk such as a CD-ROM or DVD, or controlling the amount of the fluid.